The present invention relates to an assembling structure for balance valve of cold/hot water mixing valve, and more particularly to an assembling structure including a balance valve shade board for assembling a water pressure balance valve with the bottom of the mixing valve.
It is known that a conventional cold/hot water mixing valve is installed in a faucet and directly communicated with the water transferring passage of the cold/hot water. A pair of sealedly overlaid ceramic discs in the valve serve to mix the cold and hot water and adjust the amount of the water. However, in use, in the case that one of the cold and hot water passages fails to stably supply water, the water discharged from the faucet will be alternately cold and hot. Especially, in the case that the cold water is suddenly greatly reduced or shut off while the hot water is continuously supplied, high temperature hot water will flow out from the faucet. This may lead to burn of a user. In order to avoid such danger, generally prior to connection of the cold/hot water tubes with the mixing valve, the water tubes are first connected with a balance valve device. In the case that the water pressure in one of the water tubes suddenly changes, the balance valve serves to automatically shut off the water supply of the cold and hot water tubes so as to ensure safety.
FIG. 11 shows a conventional cold/hot water mixing valve device in which a balance valve is directly disposed on the bottom thereof. The mixing valve is composed of a cartridge 3', an upper bottom board 4' and a lower bottom board 5'. In the cartridge 3' are sequentially fitted a control lever device 31', a movable disc 32' and a fixed disc 33'. A seal 41' is fitted with the top face of the upper bottom board 4' with the insertion lugs 42' latched in the latch holes 35' of the bottom of the cartridge 3'. The upper bottom board 4' is formed with a cold and hot water hole 43' and a mixing water hole 44' respectively communicating with the cold and hot water hole 331' and mixing water hole 332' of the fixed disc. The upper bottom board 4' is further formed with an upper balance valve chamber 45' under the cold and hot water hole 43'. In addition, the lower bottom board 5' is also formed with a cold and hot water hole 53' and a mixing water hole 54' respectively communicating with the cold and hot water hole 43' and mixing water hole 44' of the upper bottom board. The lower bottom board 5' is further formed with a lower balance valve chamber 55' above the cold and hot water hole 53'. The lower and upper balance valve chamber 55', 45' together sealedly accommodate therein a balance valve 2'. After assembled, the cold and hot water passage is such that the water is sent in from the water incoming tube to flow through the water hole 53' of the lower bottom board and get into the space defined by the balance valve 2'. Then the water flows from the space through the water hole 43' of the upper bottom board and the water hole 331' of the fixed disc into the mixing chamber 321' of the movable disc. When the mixing chamber 321' is communicated with the water hole 332' of the fixed disc, the mixing water flows from the water hole 332' and through holes 44', 54' into the chamber of the faucet to discharge from the spout thereof.
According to the above arrangement, the balance valve and the mixing valve are assembled into an integral body so as to ensure safety in use of the water. However, the balance valve is accommodated in a space defined by multiple components including the cartridge, upper bottom board and lower bottom board. Therefore, these components must have relatively high precision for sealedly assembling the respective components. The higher precision leads to more difficulty in processing and increased cost of production. In addition, in order to ensure the sealing of the respective components, sealing rings are fitted between the components. In the case that any of the components is disaligned during the assembling procedure, the sealing characteristic will be lost. In addition, these components are assembled with each other by insertion, latching or screws. It is hard to ensure that the components are firmly connected with each other. In the case that any of these components is loosened, the sealing effect will be lost. In conclusion, it is difficult to reliably assemble the components of the above cold/hot water mixing valve and leakage often takes place at the connection between the components.